Measurements of an ablator-gas atomic mix in indirectly driven implosions at the National Ignition Facility

• Published in: Physical review letters 2014-01, Vol.112 (2), p.025002-025002, Article 025002
• Main Authors: Smalyuk, V A, Tipton, R E, Pino, J E, Casey, D T, Grim, G P, Remington, B A, Rowley, D P, Weber, S V, Barrios, M, Benedetti, L R, Bleuel, D L, Bradley, D K, Caggiano, J A, Callahan, D A, Cerjan, C J, Clark, D S, Edgell, D H, Edwards, M J, Frenje, J A, Gatu-Johnson, M, Glebov, V Y, Glenn, S, Haan, S W, Hamza, A, Hatarik, R, Hsing, W W, Izumi, N, Khan, S, Kilkenny, J D, Kline, J, Knauer, J, Landen, O L, Ma, T, McNaney, J M, Mintz, M, Moore, A, Nikroo, A, Pak, A, Parham, T, Petrasso, R, Sayre, D B, Schneider, M B, Tommasini, R, Town, R P, Widmann, K, Wilson, D C, Yeamans, C B
• Format: Article
• Language: English
• Subjects: Ablation; Computer simulation; Deceleration; Hot spots; Ignition; Implosions; Two dimensional; X rays
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.112.025002

We present the first results from an experimental campaign to measure the atomic ablator-gas mix in the deceleration phase of gas-filled capsule implosions on the National Ignition Facility. Plastic capsules containing CD layers were filled with tritium gas; as the reactants are initially separated, DT fusion yield provides a direct measure of the atomic mix of ablator into the hot spot gas. Capsules were imploded with x rays generated in hohlraums with peak radiation temperatures of ∼294  eV. While the TT fusion reaction probes conditions in the central part (core) of the implosion hot spot, the DT reaction probes a mixed region on the outer part of the hot spot near the ablator-hot-spot interface. Experimental data were used to develop and validate the atomic-mix model used in two-dimensional simulations.